P21C9
Reductant control module power relay/relays control circuit high or Dnox-relay stuck opened
Generic OBD-II
Read & clear P21C9 yourself
Scan your car, confirm the code, and clear it once it's fixed — with OBD DashX on your phone.
Scan your car, confirm the code, and clear it once it's fixed — with OBD DashX on your phone.